Polymerase chain reaction (PCR) investigations of prepatent Schistosoma haematobium cercariae incidence in five water bodies, South West, Nigeria.

UNLABELLED: This study investigated the levels of prepatent S. haematobium infection in water samples collected from Schistosomiasis haematobium transmission namely: International Institute of Tropical Agriculture (IITA) river and Eleyele river in Oyo state, Oyan dam and Shokori river in Ogun state, Badagry Lagoon and Lagoon (University of Lagos, Lagos state). METHODOLOGY: Polymerase chain reaction (PCR) assay amplifying the Dra I repeated sequence of S. haematobium cercariae from the water samples was used. Samples of cercariae obtained from a laboratory population of Bulinus globosus and Bulinus rohlfsi snails were assayed following DNA extraction as control. Physico-chemical parameters of the water bodies were determined. RESULTS: Physico-chemical parameters showed that salinity, conductivity and total dissolved solids were relatively high in the Lagoon front samples (41.91 ppt, 62400.87 micros/cm, 31000.14 mg/L and 7.79), and low in the river samples (13.27 ppt, 1325.67 micros/cm, 11470 mg/L and 8.36 respectively) while pH were similar. PCR showed that 3 out of the 6 water bodies sampled namely IITA river, Eleyele river and Oyan Dam are S. haematobium endemic sites as they gave positive signals. CONCLUSION: Three surveyed sites with relatively low salinity namely IITA river, Eleyele river and Oyan dam are high S. haematobium endemic areas and schistosomes survive perhaps best in low salinity environment. PCR could be a more valuable tool in the study of incidence and prevalence of S. haematobium infection compared with conventional cercariae shedding method. On the known strength of focal effects of environmental conditions, implications of these results in the epidemiology and design of control activities are encouraging.

Antibacterial activities of lactic acid bacteria isolated from selected vegetables grown in nigeria: a preliminary report

Members of lactic acid bacteria (LAB) are known probiotics and have been reported to have antimicrobial properties. Although various researchers have documented the isolation of these bacteria from fruits and vegetables; studies on LAB associated with lettuce; cucumber and cabbage are limited and non-existing in Nigeria. This study was designed to assess lettuce; cucumber and cabbage as potential sources of LAB and investigate the actions of their bacterial cell supernatants (BCS) on some pathogenic bacteria. Using standard microbiological methods; isolated LAB were identified to species level with API 50 CH kits (Biomerieux; France). Cell free supernatants (CFS) from de Man Rogosa Sharpe (MRS) broth cultures of the LAB strains were used to challenge Pseudomonas aeruginosa ATCC 27853; Enterococcus faecalis ATCC 29212; Escherichia coli ATCC 12900 and Proteus penneri ATCC 13315 by agar well diffusion method. The control consisted of the sterile MRS broth subjected to the same growth conditions as LAB broth cultures. A total of four lactic acid bacteria were isolated as follows: Pediococcus pentosaceus 2 from cucumber; Lactobacillus cellobiosus from cabbage; Lactobacillus salivarius and Lactobacillus plantarum 1 from lettuce. Pediococcus pentosaceus 2 and L. salivarius showed inhibitory effects on all the standard strains tested while L. plantarum 1 showed no inhibitory activity against E. faecalis and E. coli. Lactobacillus cellobiosus showed inhibition against all except P. penneri. Although; the molecular characterisation and probiotic potentials of these LAB strains are being investigated in an on-going study; we presumed these vegetables are prospective sources of the bacteria in Nigeria and therefore the need to extensively investigate the vegetables and other related vegetables becomes imperative

Antibiotic susceptibility pattern of Staphylococcus species isolated from telephone receivers.

INTRODUCTION: Microorganisms are transferred to everyday objects from the environment and infected individuals. Pathogenic microbes are transmissible from the air, skin, hands and other interpersonal contacts and cause diseases most of the time. This study centres on the microbial assessment of telephone receivers, their ability to transfer bacterial infections and the isolation of these microorganisms from receivers, with an emphasis on Staphylococcus aureus and its antibiotic susceptibility pattern. METHODS: 1,591 isolates were obtained from roadside telephone booths in 16 different locations in the Lagos metropolis. They were all characterised using the Cowan and Steel's manual, after which the antimicrobial susceptibility pattern of the most frequently-occurring isolate was determined. RESULTS: Of all the locations, Oshodi was found to have the largest number of microorganisms, with Akoka having the least. The organisms were Providencia, Klebsiella, Citrobacter, Enterobacter, Proteus, Escherichia, Staphylococcus, Bacillus, Streptococcus, Micrococcus and yeast. Staphylococcus spp. was the most frequently occurring, making up 20.2 percent of the total number of isolated organisms, followed by Bacillus (18 percent), while Enterobacter and Citrobacter were the least common. 44 percent of the total Staphylococcus screened for an antimicrobial susceptibility pattern showed high resistance to most of the antibiotics used. CONCLUSION: This result could be related to the emergence of Staphylococcus-resistant strains, especially in a highly-populated area where there are health and hygiene problems and where drugs are abused. Precautions should be taken to prevent the spread of infectious diseases through the use of public telephones.

Molecular epidemiology of methicillin-resistant Staphylococcus aureus in Ilorin, Nigeria.

BACKGROUND: Nosocomial infections caused by methicillin-resistant strains of Staphylococcus aureus constitute significant epidemiologic problems. Defining an outbreak requires the use of rapid and highly discriminatory epidemiologic methods to determine the epidemic strains involved in such outbreak. STUDY DESIGN: A descriptive laboratory based surveillance study for MRSA was undertaken. One hundred and forty seven Staphylococcus aureus isolates from clinical specimens were screened for methicillin resistance at the University of Ilorin Teaching Hospital between January and December 2001. Fifty one (34.7%) methicillin resistant strains recovered were epidemiologically characterized using Eco R1 restriction enzyme analysis of their plasmid DNAs. RESULT: Forty five (88.2%) MRSA isolates were associated with infections and 6 (11.8 %) were colonizing strains; 36 (70.6%) and 15 (29.4%) were hospital and community acquired respectively. Skin and soft tissues were sites of infection in 36 (70.6 %) cases and surgical, emergency and ICU accounted for 33 (64.7%) isolates. All isolates were resistant to more than two antibiotics but sensitive to vancomycin. Forty two (82.4 %) isolates contained plasmids including 9 (21.4 %) that contained more than one plasmid. Restriction Enzyme Analysis of the Plasmid DNA (REAP) divided the isolates into 9 Eco R1 profiles, with profile 2 accounting for 41.7% of all nosocomial infections in the wards, implying that it is endemic. The remaining nosocomial profiles occurred less frequently, suggesting that they are sporadic strains originating from outside the hospital. The community strains showed diverse digestion pattern indicating that they are from different clones. CONCLUSION: The spread of MRSA can be controlled through reinforcement of appropriate use of antibiotics, hand washing and laboratory surveillance for MRSA, particularly in the surgical wards and intensive care units, in order to identify sources of outbreaks.

Epidemiology of shigellosis in Lagos, Nigeria: trends in antimicrobial resistance.

Antimicrobial susceptibility of Shigella spp. and Escherichia coli, isolated from diarrhoeal patients in Lagos, was studied from March 1999 to February 2000. Four hundred fifty-nine isolates were identified as shigellae (62) and E. coli (397). Shigella flexneri, S. dysenteriae, S. boydii, and S. sonnei accounted, respectively, for 51.6%, 17.7%, 17.7%, and 13% of the total number of shigellae isolated. Eleven cases of shigellosis occurred in the age group of 0-9 years, 22 cases in the age group of 10-19 years, and 29 cases in the age group of > or = 20 years. Of the 397 E. coli isolates, 11 were enteropathogenic E. coli (EPEC), and 7 of these strains were isolated with shigellae from stools of patients aged 0-9 year(s) (71.4%) and 10-19 years (28.6%). Over 70% of the Shigella isolates were resistant to two or more drugs, including ampicillin and tetracycline. Twenty-one distinct multidrug resistance patterns were observed in these isolates. During 1990-2000, resistance to ampicillin increased from 70% to 90%, co-trimoxazole from 77% to 85%, chloramphenicol from 71% to 77%, streptomycin from 71% to 79%, and nalidixic acid from 0% to 11.3%. Resistance to tetracycline decreased from 89% to 79% but with MIC50 and MIC90 values outside the susceptible range. While resistance to ciprofloxacin and ofloxacin remained nil with MIC50 and MIC90 values of 0.008 and 0.0016 microgram/mL respectively. The results of this study revealed the endemicity of shigellosis with S. flexneri as the predominant serogroup in Lagos. Children and young adults were at a higher risk of severe shigellosis. The results also suggest that ampicillin, tetracycline, co-trimoxazole, and streptomycin should not be used as the first-line drugs in the treatment of shigellosis. Nalidixic acid should still be selectively used for treatment, while ciprofloxacin and ofloxacin can be ideal alternatives.

Antidiarrhoeal activities of Ocimum gratissimum (Lamiaceae).

The antidiarrhoeal activities of leaf extracts of Ocimum gratissimum were investigated by disc diffusion and tube dilution methods. The extracts were active against Aeromonas sobria, Escherichia coli, Plesiomonas shigelloides, Salmonella typhi, and Shigella dysenteriae. The leaf extracts were most active against S. dysenteriae and least active against S. typhi. The sensitivity of the organisms measured in terms of zone of inhibition ranged from 8.00 to 19.50 mm. The minimum inhibitory concentrations were from 4.00 to 50.00 mg ml-1, while the minimum bactericidal concentration ranged from 8.00 to 62 mg ml-1. The potentials of the leaf extract for the treatment of diarrhoeal diseases is discussed.